Blender (Cycles Render) Normal Map Baking goes wrong
Your normals are inverted. Some of them are broken appart (they are not united) try going into edit mode and move them, you´ll see how they get appart and break from the original mesh. You got all traces needed since the normal map already tells you where this is happening. ALT+M will join vertex together (choose AT CENTER).

Another solution is to check out the normals. Definelty looks like the ones you have problems with are INVERTED NORMAL faces. Delete them from your model, recreate them in EDIT MODE and then select your object CTRL+N to average normals while in edit mode. Hope that fixes. It will certainly.
Cheers.